From the Greek word for "Similar To
A Sesame Seed", the word Sesamoid refers to two small bones you
have in the ball of the foot beneath and behind your big toe
joint. (You also have them in your thumb joint, but we're not
concerned about those sesamoids here.)

What do sesamoids
do?

The sesamoids act like pulleys, to help
and improve the efficiency and function of the flexor tendons (the
tendons on the bottom of the foot which help bend your big toe
down).

Your knee cap (patella) functions in the
same way, and can be thought of as large sesamoids.

The two small, circular
bones behind the big toe are the sesamoid bones

Seen from the view on the right, the
sesamoids are clearly seen beneath the first metatarsal
bone:

So what can go wrong
with your sesamoids?

The most common thing to go wrong is the
development of sesamoiditis, a condition where the
sesamoids become inflamed, usually from repetitive trauma.

If the sesamoids are traumatized past the point
of simple irritation, they may become break, a condition known as a fractured
sesamoid. This condition has to be differentiated from that of bipartite
sesamoids, a normal variant where instead of two sesamoids, a patient may
have sesamoids made up of multiple pieces. As you might imagine, this can look
very similar to a fractured sesamoid, so a thorough assessment by a foot
specialist is essential to accurately diagnose the problem.

How do you treat sesamoid
injuries?

We have a fairly large arsenal of treatments that
can be employed to treat sesamoiditis. Rest, ice, compression, elevation,
padding, orthoses, medications, shoe changes, physiotherapy and other treatments
have been used successfully for this condition.

The difficulty, however, is that the sesamoids
have very poor blood supply, and coupled with the forces exerted on the bones
from weight bearing and from the pull of the tendons, sesamoids often heal very
slowly. Sometimes they don't heal at all, despite proper diagnosis and
treatment.

What do you do then?

If they're painful and don't respond to
treatment, the problem sesamoid may have to be removed. While this
may seem simple, sometimes the toe begins to drift in one direction or the other
after the surgery (depending upon which sesamoid is removed), and additional
procedures may have to be considered to stabilize the toe.